How to scan a film?

On the cheap I recently scanned B&W and color negatives with my Pentax K5 and would assume other cameras have the same type of "filter" the reveres the exposure/color.

used a rubbermaid storage container with a shop light as a light box and some glass from old pic frames to create a work surface . The results we in par with scanners I have used in the past except for dust and scratch removal that comes with scanners